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Data and Picture Interpretation Stations: Cases 1–45
Published in Peter Kullar, Joseph Manjaly, Livy Kenyon, Joseph Manjaly, Peter Kullar, Joseph Manjaly, Peter Kullar, ENT OSCEs, 2023
Peter Kullar, Joseph Manjaly, Livy Kenyon, Joseph Manjaly, Peter Kullar, Joseph Manjaly, Peter Kullar
The thyroid parenchyma consists of follicular cells and the parafollicular or C-cells. Differentiated thyroid cancer includes follicular, Hurthle cell and papillary thyroid cancer. The parafollicular cells give rise to medullary thyroid carcinoma. Thyroid function tests should be requested for patients presenting with a thyroid nodule as patients with hyperthyroidism are less likely to have malignancy and a radionuclide uptake scan is indicated. In all other cases a thyroid ultrasound with FNA is indicated. Surgical excision remains the primary treatment of differentiated thyroid cancer with postoperative radioiodine ablation depending on the staging. Medullary thyroid cancer is treated by total thyroidectomy with neck dissection. Radioiodine is not used for medullary thyroid cancer given the distinction in embryological origin of it and differentiated thyroid cancer.
Thyroid Hormones and Calcium Metabolism
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The functional units of the thyroid gland are the follicles (acini). They are made up of a single layer of cuboidal epithelial cells with a central lumen filled with colloid, which is predominantly a glycoprotein, thyroglobulin. Parafollicular cells (C cells), which secrete calcitonin, are scattered between the follicles. Thyroid hormone synthesis and release is regulated by a negative feedback by the hypothalamic–pituitary–thyroid axis. Thyroid-releasing hormone is released from the median eminence of the hypothalamus and transported to the anterior pituitary gland, where it stimulates the release of TSH.
Biochemistry
Published in Burkhard Madea, Asphyxiation, Suffocation,and Neck Pressure Deaths, 2020
The thyroid gland, bilobular in structure and located at the front of the neck, is made up of two types of endocrine cells called follicular and parafollicular cells. The former (also called thyrocytes) are responsible for thyroglobulin (Tg) synthesis. The latter (also known as C-cells) secrete the hormone calcitonin, which is involved in calcium homeostasis [12].
The possible ameliorative role of Lycopene on Tributyltin induced thyroid damage in adult male albino rats (histological, immunohistochemical and biochemical study)
Published in Ultrastructural Pathology, 2023
Ghada A Elsammak, Aliaa Talaat, Samar Reda
H&E stained sections of the thyroid gland of the control group showed thyroid follicles lined by cuboidal follicular cells with central rounded nuclei. There was acidophilic and homogenous colloid filling in the luminae of the follicles. The parafollicular cells were small oval with dark stained nuclei and situated between the follicular cells on the basement membrane (Figure 1a). The TBT-treated group showed some follicles lined by cuboidal cells with rounded nuclei and others lined by flat cells with flat nuclei. Numerous follicular cells showed vacuolated cytoplasm. In some follicles, multiple layers of follicular cells were seen on one side. There were large interstitial spaces between some follicles. Some follicles were dilated while others were involuted. There was a large congested blood vessel. There were numerous darkly stained nuclei. The capsule was noted. Some follicles had no colloid (Figure 1b). The protective (TBT-Lycopene) group showed nearly normal thyroid architecture. Thyroid follicles were of variable sizes. Almost all the follicles were filled with colloid and showed peripheral vacuolations. Most of thyroid follicles were lined by cuboidal cells with large rounded central nuclei while some follicles were lined by flat cells with flat nuclei. Few follicles showed vacuolated cytoplasm and dark nuclei. Groups of interfollicular cells were present in between follicles. Two fused follicles were seen (Figure 1c).
Insights into the possible impact of COVID-19 on the endocrine system
Published in Archives of Physiology and Biochemistry, 2023
Adel Abdel-Moneim, Ahmed Hosni
A study performed during the 2003 SARS-outbreak recorded lower levels of serum T3 and tetraiodothyronine (T4) in patients with SARS compared with controls (Wang et al.2003). In addition, intensive care cases of SARS with sick-euthyroid syndrome seemed to have a lower thyroid weight related to decreasing follicular thyroid size along with colloid depletion (De Jongh et al.2001). Multiple pathways have been proposed for the progression of sick-euthyroid syndrome, including changes in iodothyronine deiodinases and TSH secretion, thyroid hormone binding to plasma protein, thyroid hormone delivery in peripheral tissues, and thyroid hormone inhibitory effects (DeGroot 2000). Moreover, Sun et al. (2005) identified follicular cell dystrophy, deformation, and decrease levels of thyroglobulin in four patients with SARS who died. Furthermore, autopsy investigations of five patients with SARS showed considerable degradation of the thyroid follicular and parafollicular cells with significant numbers of cells undergoing apoptosis (Wei et al. 2007). Destruction of the thyroid follicular cells can be manifested by low T3 and T4 levels.
The possible protective role of vitamin C versus melatonin on potassium dichromate induced changes in rat thyroid gland: light and electron microscopic study
Published in Ultrastructural Pathology, 2023
Eman Saeed, Ahmed A. El-Mansy, Shireen A Mazroa, Amal M. Moustafa
The thyroid gland of the control group showed the same structure in the different subgroups (Іa, Іb and Іc). The stroma was formed of a thin capsule and septa dividing the gland into incomplete lobules. The thyroid parenchyma was composed of thyroid follicles and separated by interfollicular tissue. The thyroid follicles were variable in shape and size. The central follicles had a smaller diameter than the peripheral ones. The thyroid follicles were lined mainly with follicular cells and a small number of parafollicular cells. The central follicles were lined by cubical follicular cells with large, rounded nuclei, whereas the peripheral ones were lined with low cubical or flat follicular cells with flat nuclei. The thyroid follicles exhibited a central acidophilic homogenous colloid that revealed marginal vacuoles (Figure 1(a,b,c)). Parafollicular cells were rarely seen in the section. They were resting on the basement membrane and did not reach the luminal surface. They were few in number, large in size, rounded or oval in shape with vesicular nuclei and pale stained cytoplasm (Figure 1(a,b)). The interfollicular tissue was composed of a scanty amount of C.T. containing blood vessels, fibroblast and interfollicular cells, which were seen among the thyroid follicles (Figure 1c).